There is a widely acknowledged national shortage of translationally trained young investigators, both Ph.D.s and M.D.s. To accomplish this goal, the Reproductive &Developmental Biology Training Program at the Massachusetts General Hospital selects strongly motivated candidates from a rich candidate pool;provides trainees with an intensive research experience in basic and/or clinical investigation;supports these efforts with a skilled and well-funded faculty engaged in important research questions;and complements this mentored research experience by a strong didactic experience in the underpinning sciences of genetics, reproductive and developmental biology and clinical investigation. Trainees are selected on the basis of prior academic and research accomplishments;a strong future commitment to an academic career;and a personal interview indicating their motivation and future potential as independent investigators. The PI (Dr. Crowley) is a Professor of Medicine at Harvard Medical School, Director of the Harvard Reproductive Endocrine Sciences Center, an established scientist and recognized mentor who governs in conjunction with Dr. Patricia Donahoe, a highly qualified senior scientist, who serves as Co-Director. The training faculty consists of active, well-funded scientists whose expertise lines the full spectrum of reproductive and developmental research from fundamental developmental biology to bench-to-bedside investigations. The training faculty has been expanded in this proposal to reflect and take appropriate advantage of the new tools and opportunities that are redefining translational research. Each trainee is closely supervised by an active yet individualized mentorship program overseen by a senior faculty member. An extensive and rigorous didactic program interlaces tightly with their strong, independent laboratory programs and compliments the trainees'2-3 years of research experience (90%effort). The training period often involves additional years as junior faculty to ensure maximal competitiveness for subsequent independent support, the ultimate goal of this Training Program. Research facilities are spacious and fully equipped with recently modernized laboratory and clinical research space dedicated to the training faculty of this grant. The institutional environment is superb and the reinforcement from the Reproductive Endocrine Sciences Centers programs is substantial. This institutional training grant represents a critical stabilizing element in these programs and is a critical link that enables talented trainees to achieve subsequent independent careers in Reproduction and Developmental Biology.